docs: def get_mean_and_stddevs(self, sites, rup, dists, imt, stddev_types):
          """
          See :meth:`superclass method
          <.base.GroundShakingIntensityModel.get_mean_and_stddevs>`
          for spec of input and result values.
          """
          assert all(stddev_type in self.DEFINED_FOR_STANDARD_DEVIATION_TYPES
                     for stddev_type in stddev_types)
  
          # extract dictionaries of coefficients specific to required
          # intensity measure type
          C = self.COEFFS[imt]
  
          # Deltas for Tectonic Region Type and rake angles
          delta_R, delta_S, delta_V, delta_I = self._get_deltas(rup.rake)
  
          mean = self._compute_mean(C, rup.mag, dists.rrup, rup.hypo_depth,
                                    delta_R, delta_S, delta_V, delta_I,
                                    sites.vs30)
  
          stddevs = self._get_stddevs(C, stddev_types, sites.vs30.size)
  
          return mean, stddevs